Another thing to remember is how easy it is to print QR code stickers and just stick those over legitimate stickers at restaurants, events, stores, offices, banks, etceteras. They look the same to you.
So even a code it seems you are expected to scan could be a malicious one.
I am once again reminding you that scanning random QR codes is upsettingly close to plugging a random flash drive you found into your laptop.
Do not do the thing.